Isn't this sorta like when the FBI knew about Muslims who wanted to learn to fly, but didn't want to learn how to land? DHS IG: Tunnels Along U.S.-Mexico Border ‘Significant and Growing’ Threat

DHS IG: Tunnels Along U.S.-Mexico Border ‘Significant and Growing’ Threat:
"According to a report by the DHS OIG released December 11, the Customs and Border Protection (CBP) agency, charged with protecting the U.S. borders, lacks the technological capability to detect subterranean tunnels.
“Illicit cross-border tunnels along the southwest border are primarily used by criminals to transport illegal drugs into the United States, and they are a significant and growing threat to border security,” noted the report.
“In an effort to counter this threat, CBP has modified its operations through patrols, intelligence gathering, and closing of illicit cross-border tunnels, but it does not yet have the technological capability to detect the tunnels routinely and accurately.”"